Best BQ series bass head compatible with Ashdown 1x15

Tried out a BQ500 with a TC 115 cab last week and really liked it.

I have an Ashdown 115 300w cab rated at 8 ohms and I wondered which BQ would be best rated to power it. I play small pubs and halls and rarely DI.

Keen also to understand how the BQ and RH series rate against the BQ series.